MSLN and pancreatic adenocarcinoma: Mesothelin (MSLN), a membrane-bound surface glycoprotein, is highly expressed in multiple solid tumors [such as pancreatic adenocarcinoma (PDAC), malignant pleural mesothelioma (MPM), and OC], but positive in limited kinds of normal tissues including pleura, peritoneum, pericardium, and epithelium of trachea.